Subject: Re: Znyx multi channel ethernet cards
To: Graham, James <James.Graham@Schwab.COM>
From: Brett Lymn <>
List: current-users
Date: 04/09/1997 18:55:55
According to Graham, James:
>Since you're presumably on different networks, there is no reason
>to do otherwise.  It saves having to have an address ROM on
>each port of an interface.  If you have a quad card, what, are
>you going to put a ROM on each IF?

As others have pointed out the storage is not the issue.  Not having a
different MAC address per interface is not silly in a switched
ethernet environment - the ethernet switching relies on it.  If an
ethernet switch sees the same MAC address in two collision domains it
will get very confused, here at work I have had to hack Sun's start up
scripts to set the MAC address on a machine's interfaces (yes you CAN
do that on a Sun) that participate in our switched ethernet to
different values so that the switching will work correctly.

.... the attribution of the below comment is fuzzy - dunno who it was
who said:
>'cause its illegal...each device on each net must have a globally
>unique address. The fact that you can make it work is irrelevent.

But it is not illegal.  Apparently the IEEE standard for ethernet says
that the ethernet _node_ must have a unique MAC address.  This is what
Sun (are there any others???) did.

Brett Lymn, Computer Systems Administrator, AWA Defence Industries
  "Upgrading your memory gives you MORE RAM!" - ad in MacWAREHOUSE catalogue.